Submersible pump



April 21,1970 E. B. WATSON 3,507,602

SUBMERS IBLE PUMP Filed July 17, 1968 United States Patent 3,507,602SUBMERSlBLE PUMP Earnest B. Watson, 627 Main St., Osawatomie, Kans.66064 Filed July 17, 1968, Ser. No. 745,569 Int. Cl. F04d 3/02 U.S. Cl.415-72 1 Claim ABSTRACT OF THE DISCLOSURE A submersible pump for use inoil wells and the like consisting of a housing adapted to be attached toa tubular delivery pipe to be lowered into a well and having an inletopening, a driven auger enclosed in a tube integral therewith mountedrotatably within said housing, said auger tube having clearance from thehousing walls to prevent friction and having its open ends communicatingrespectively with said inlet opening and said delivery pipe, and venturimeans powered by the pump action to prevent leakage of pumped fluidaround said enclosed auger within said housing.

This invention relates to new and useful improvements in pumps, and hasparticular reference to pumps of the submersible type commonly used inoil wells and the like. Such pumps must of course develop a highdelivery pressure in deep wells to elevate the oil to the groundsurface, and are also subject to considerable abrasive wear from thesand, grit and other solid impurities entrained in the oil. Accordingly,the principal objects of the present invention are the provision of apump of the character described which is capable of developing thedelivery pressures required with a structure much less complicated thanhas heretofore been required in pumps of this general class, and whichhas novel provisions for reducing the abrasive wear thereof by theforeign matter entrained in the oil.

My invention may be summarized as the provision of a pump consisting ofa tubular housing having an outlet opening adapted to be interconnectedwith a delivery pipe to be lowered into a well to a point beneath theliquid level therein, and an inlet opening spaced apart from said outletopening longitudinally of said housing, an anger mounted concentricallyin said housing intermediate said inlet and outlet openings, said augerhaving an enclosing tube integral and concentric therewith, there beingsub stantial annular clearance between said auger tube and said housing,means for driving said auger, and venturi members at the exit end ofsaid auger and operable by the velocity of the oil as it emerges fromsaid auger to tend to create an upward suction in the annular clearancespace between the auger tube and the housing, thereby tending to preventreverse flow of oil through said clearance space.

With the above described objects in view, as well as other objects whichwill appear in the course of the specification, reference will be had tothe accompanying drawing, wherein:

FIG. 1 is a side elevational View of a submersible pump embodying thepresent invention, shown operatively attached to a delivery pipe,

FIG. 2 is an enlarged, foreshortened fragmentary sectional view taken online IIII of FIG. 1, with parts left in elevation,

FIG. 3 is a sectional view taken on line III--III of FIG. 6 is asectional view taken on line VIVI of FIG. 2, and

3,507,602 Patented Apr. 21, 1970 FIG. 7 is a sectional view taken online VII-VII of FIG. 2.

Like reference numerals apply to similar parts throughout the severalviews, and the numeral 2 applies to the pump housing. Said housing is inthe form of a cylindrical tube, having a cap 4 threaded into its upperend, into which the delivery pipe 6 is in turn threaded, said pipecommunicating with the interior of the housing. Said pipeof courseextends to the ground surface, and serves to support and position thepump in an oil well or the like, it being understood that the pump iswhen in use lowered to a point beneath the liquid level in the well andthereby submerged in said liquid. At its lower end, housing 2 has atubular extension 8 threaded therein, said extension having a largenumber of narrow apertures 10 formed therein to permit the entry of oil.At its lower end, extension 8 is threaded on the mounting ring 12 of asealed electric motor 14, the drive shaft 16 of said motor extendingupwardly into extension 8 coaxially with housing 2. In cap 4, there ismounted a check valve 18 adapted to permit upward flow of pumped liquidfrom the housing into delivery pipe 6, but to prevent reverse flow. Saidvalve is mounted on a stem 20 which is vertically slidable in a bearingsleeve 22 carried in cap 4 by a spider support 24, and cooperates with avalve seat 25 formed in a partition wall of said cap.

Mounted coaxially in housing 2, and extending substantially the fulllength thereof, is an enclosed pump auger 26 including a vertical shaft28, helical auger flights 30 and 32, and an enclosing tube 34. Saidshaft, flights and tube are essentially integral, comprising a unitarystructure, although they may of course be formed separately and laterassembled. Shaft 28 is journalled at its upper end in a bearing sleeve36 supported axially in the housing by a spider support 38, and issimilarly journalled adjacent its lower end in a bearing sleeve 40supported axially in the housing by spider 42. Said shaft extends belowbearing 40, and is connected to motor drive shaft 16 by coupling 44, soas to be rotatably driven thereby. Eleceric current is supplied to motor14 by a moistureproof electric cable 46 extending down from the groundsurface, being aflixed at intervals to delivery pipe 6 by clips 48, andto housing 2 by clips 50.

Auger tube 34 is open at both ends, so that oil or other liquid to bepumped can flow therethrough by passing helically about shaft 28 betweenflights 30 and 32, and the auger is turned in such a direction(clockwise as viewed in FIG. 5) that liquid trapped therein is forced tofollow this upward path, due to the upward incline of the flights in adirection opposite to the direction of rotation, and due to the inertialtendency of the liquid to lag behind the speed of rotation of theflights. However, as the liquid approaches the upper end of the augerits rotational speed closely approaches that of the auger, due to thefact that auger tube 34 rotates with the flights, and the liquid istherefore not subject to the frictional drag which would occur if theauger flights rotated in a fixed tube, as in the usual auger conveyor.Therefore, in the upper portion of the auger, there is actually only avery slight lift imparted to the liquid as compared to the lift of theflights themselves. For example, while one rotation of the auger wouldcause a flight lift equal to the pitch of one of the auger flights, theliquid might be elevated only perhaps 5% of this amount, since it isrotating at perhaps of the auger speed. For this reason, the pump candevelop a very substantial delivery pressure, fully adequate to pumpreasonably deep wells. This represents a substantial simplification overthe usual multistage turbine impellers commonly employed in pumps ofthis general nature. A plurality of flights are preferable to a singleflight in the auger, in order to provide better balancing of theoperating load on said auger. While an auger having two flights isactually shown, three or even four flights could be used if desired.

In order to alleviate the abrasive wear common in submersible pumps,resulting from sand, grit and other foreign matter often entrained intheoil, water or other liquid being pumped, an annular clearance 52 isprovided between the exterior surface of auger tube '34 and the internalsurface of housing 2, the thickness of said clearance being greater thanthe diameter of the largest particle of foreign matter likely to beencountered. This can be accomplished by making the radial thickness ofsaid clearance greater than the width of the entry apertures of housingextension 8. This of course alleviates the abrasive wear as desired, butliquid could also flow from the top to the bottom of the housing throughclearance space 52, thus short-circuiting the pump, if means were notprovided to prevent this return flow. Ordinary types of seals such asgaskets, ring seals or the like, are not practical, since they involverelative movement of surfaces either contacting or nearly contactingeach other, and would hence themselves be subject to abrasive wear.

In the present structure, the sealing problem is solved by leavingannular passage 52 entirely open, and providing means operable by theauger action to produce an upward suction in said passage, the suctionin some circumstances producing an actual upward flow of liquid in saidpassage, but being at least sufiicient to reduce downward flow in saidpassage to tolerable limits, whereby to provide pumping action ofacceptable efficiency. To this end, the extreme upper end portion ofauger tube 34 is conically reduced to provide a lip 54 which convergesupwardly in the direction of liquid flow. Said lip rotates within anannular ring 56 fixed in housing 2 being conveniently formed as a partof an element including upper bearing sleeve 36 and spider 38. Thecentral aperture, of said ring is conical to conform with the outersurface of lip 54, but is spaced apart from said lip to provide aconical passage 58 therebetween, said passage communicating at its lowerend with the annular clearance 52 between auger tube 34 and housing 2,and opening at its upper end into housing 2 above'ring 56. Lip 54extends flush with the upper face of ring 56.

In operation, the lip 54 reduces the diameter of the column of liquidwithin the auger tube as said liquid passes through said lip, with theresult that as the liquid emerges from the upper end of said lip, it iscaused by its high rotational speed, which as previously described maybenearly as great as the peripheral speed of the auger, to flow radiallyoutwardly by centrifugal force, thereby passing with high velocity overthe upper end of conical passage 58. This action, by the well knownVenturi principle, creates a zone of greatly reduced pressure, onsuction, in and immediately above the upper portion of passage 58, thustending to draw liquid upwardly through annular clearance space 52, andcombating the tendency of the pressure head in delivery pipe 6 to forceliquid downwardly through said clearance space to short circuit theauger. As previously indicated, it is not essential that upward flow ofliquid actually takes place in space 52, although this may occurespecially when pumping against smaller pressure heads. It is necessaryonly that the suction be of sufficient magnitude that reduces anydownward flow in space 52 to a sufficient degree that the pump canoperate with a reasonable and acceptable degree of efficiency.

It is considered that the operation of the pump has been adequatelydescribed in connection with the foregoing description of itsconstruction. It will be readily apparent that a pump has been producedwhich solves or greatly alleviates two of the most prevalent problemsusually occurring in connection with submersible pumps for use in wells.First, it provides good delivery pressure with a structure far simpler,and hence far more economical, than the complicated structures usuallyemployed, and second, it virtually eliminates abrasive wear by grit orother solid matter entrained in the liquid being pumped.

While I have shown and described a specific embodiment of my invention,it will-be readily apparent that many minor changes of structure andoperation could be made without departing from the spirit of theinvention as defined by the scope of the appended claim.

What I claim as new and desire to protect by Letters Patent is:

1. A submersible pump comprising:

(a) a cylindrical tubular housing having an inlet opening at oneendthereof, and an outlet opening at its opposite end,

(b) a helical auger enclosed coaxially within and affixed to anopen-ended cylindrical auger tube, said auger tube being disposedcoaxially within said housing intermediate the ends thereof for rotationon its axis, there being an annular clearance space between said housingand said auger tube,

(0) means carried by said housing for rotatably driving said auger in adirection to impel liquid in 'said housing toward said outlet opening,and

(d) means operable to produce a suction force at the end of said annularclearance space closest to said outlet opening, thereby tending toproduce a flow of liquid in said clearance space toward said outletopening, said suction producing means comprising cooperating memberscarried respectively by said housing and said auger tube whereby saidannular clearance space is taperingly reduced in diameter at the end ofsaid auger closest to said outlet opening, and wherein said housingimmediately adjacent the reduced end of said clearance space is ofgreater internal diameter than the reduced end of said clearance space,whereby liquid emerging from said auger tube is forced radiallyoutwardly at high speed by centrifugal force over the adjacent end ofsaid clearance space, whereby to create a zone of reduced pressure orsuction therein.

References Cited UNITED STATES PATENTS 815,224 3/1906 Sjostrom 103-91968,829 8/1910 Bennett 10393 1,587,361 6/1926 Barton 103-90 1,698,2871/1929 Westgard 103--89 2,483,335 9/1949 Davis 10389 2,647,467 8/1953Davis 10389 2,968,249 1/1961 Cain et al. 10387 FOREIGN PATENTS 26,5861909 Great Britian.

HENRY T. RADUAZO, Primary Examiner US. Cl. X.R. 415l21, 501

